Content is distributed in computer systems or by other technologies in different situations. For example, advertisements can be used in an attempt to inform people about a wide variety of products, goods, and services. Generally, advertisers may seek to target the content of their advertising to the intended audience or viewers.
Advertisements can take many forms, such as printed material, commercials on television and radio, billboards, and online advertising. These advertisements can be placed without detailed knowledge about the potential viewers with the intention of reaching potential customers who encounter the advertisement coincidentally. In some cases, advertisements are placed to target a particular demographic group (e.g., ads for toys in a children's' TV show or billboards for tires along a roadside) in order to increase the chances of reaching potential customers.